1. Field of the Invention
The present invention relates to a polymer having highly controlled molecular structure, a surface modifier for inorganic materials using the polymer, and a modified inorganic material using the modifier. In more detail, the present invention relates to a polymer having a hydrolyzable silanol group at the terminal and/or central part in the molecule. In addition, the present invention also relates to a surface modifier which affords desired dispersibility when applied for modifying pigment and other inorganic fine particles, and which affords such functions as adhesive, wetting and water-repellent properties when applied for treating the surface of the inorganic material. The present invention further relates to an inorganic material whose surface is modified by the surface modifier.
2. Description of the Prior Art
Hitherto in order to improve affinity and adhesivity between and an organic material and an inorganic material, surfactants and coupling agents (e.g. chromium-type, silane-type, titanium-type) have been utilized. Among them, the silane coupling agents have been most extensively used because of high performance after modification and their cheap cost [E. P. Plueddemann: "Silane Coupling Agents," Plenum, N.Y., 1982].
Japanese Kokai Publication No. 95326/1981 discloses a pigment-dispersing liquid which is a copolymer having at least one alkoxysilyl group. In Japanese Kokai Publication No. 20197/1987, a block copolymer of p-alkoxysilylstyrene and styrene is disclosed.
The pigment dispersing liquid as described in the above Japanese Kokai Publication No. 95326/1981, however, gives rise to a problem of secondary aggregation of the pigment after the treatment, because the alkoxysilyl groups are present in unspecified position of the polymer molecule and tend to cause gelation between the resins and bridging among pigment particles. The block copolymer, as described in the above Japanese Kokai Publication No. 201917/1987, also has a problem in production. It is difficult that p-alkoxysilylstyrene is introduced in a specific position of the polymer molecule in a controlled amount, because the p-alkoxysilylstyrene have an extremely large polymerization rate. In addition, the silane coupling agents, have a relatively low molecular weight and therefore do not afford sufficient wettability or dispersibility as surface modifiers.